808 research outputs found

    On the Impact of Channel Cross-Correlations in High-Sensitivity Receivers for Galileo E1 OS and GPS L1C Signals

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    One of the most promising features of the modernized global navigation satellite systems signals is the presence of pilot channels that, being data-transition free, allow for increasing the coherent integration time of the receivers. Generally speaking, the increased integration time allows to better average the thermal noise component, thus improving the postcorrelation SNR of the receiver in the acquisition phase. On the other hand, for a standalone receiver which is not aided or assisted, the acquisition architecture requires that only the pilot channel is processed, at least during the first steps of the procedure. The aim of this paper is to present a detailed investigation on the impact of the code cross-correlation properties in the reception of Galileo E1 Open Service and GPS L1C civil signals. Analytical and simulation results demonstrate that the S-curve of the code synchronization loop can be affected by a bias around the lock point. This effect depends on the code cross-correlation properties and on the receiver setup. Furthermore, in these cases, the sensitivity of the receiver to other error sources might increase, and the paper shows how in presence of an interfering signal the pseudorange bias can be magnified and lead to relevant performance degradatio

    Impact of non-idealities on GNSS meta-signals processing

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    This paper deals with the concept of GNSS meta-signal processing, defined as the coherent process of two GNSS signals, broadcast on different carriers, and treated as a single wideband signal. The purpose of the paper is twofold: to analyse the effects on non-idealities on the meta-signal components and to investigate alternative schemes for the actual implementation inside the receiver

    Triage in the COVID-19 Pandemic Bioethical and Human Rights Considerations

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    Laugier-Hunziker Syndrome: An Uncommon Cause of Oral Pigmentation and a Review of the Literature

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    Laugier-Hunziker syndrome is a rare benign condition characterized by diffuse oral hyperpigmentation associated with pigmentation of the nails. The syndrome must be included in the differential diagnosis of diffuse oral pigmentation to exclude other conditions with systemic implications. We describe a 43-year-old white woman with the clinical and histological features of Laugier-Hunziker syndrome associated with toenail pigmentation. The correct clinical identification avoids the need for detailed investigations and treatment. We also review the potential causes of oral pigmentation

    Path Clustering Based on a Novel Dissimilarity Function for Ride-Sharing Recommenders

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    Ride-sharing practice represents one of the possible answers to the traffic congestion problem in today's cities. In this scenario, recommenders aim to determine similarity among different paths with the aim of suggesting possible ride shares. In this paper, we propose a novel dissimilarity function between pairs of paths based on the construction of a shared path, which visits all points of the two paths by respecting the order of sequences within each of them. The shared path is computed as the shortest path on a directed acyclic graph with precedence constraints between the points of interest defined in the single paths. The dissimilarity function evaluates how much a user has to extend his/her path for covering the overall shared path. After computing the dissimilarity between any pair of paths, we execute a fuzzy relational clustering algorithm for determining groups of similar paths. Within these groups, the recommenders will choose users who can be invited to share rides. We show and discuss the results obtained by our approach on 45 paths

    Fishes and their parasites in the water district of Massaciuccoli (Tuscany, Central Italy)

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    This study has been conducted in the district of Massaciuccoli (lake, marsh and reclaimed areas with drainage channels) in Tuscany region (Central Italy). The aim of the research was to detect the presence of parasites in fishes, in particular of Opisthorchis felineus, which causes an important zoonosis. Between 2010-2012, the health status of 381 fishes was monitored, morphometric characteristics were determined, and parasites were searched for and identified. Of the 381 examined fishes, 189 were free of parasites while 192 were infected, among them 91 presented multiple infections. Opisthorchis felineus was not found in any of the examined fishes

    Effects of a clove oil extract on eggs and second-stage juveniles of Meloidogyne incognita (Kofoid et White, 1919) Chitwood, 1949

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    Trials were carried out in vitro to evaluate the action against Meloidogyne incognita (Kofoid et White) Chitwood of the clove oil extract ABT-EU04® (Xeda International S. A.), whose active principle is derived from buds of Syzygium aromaticum (L.) Merrill et Perry. Three aqueous concentrations of the product (0.125%, 0.25% and 0.50%) were tested on M. incognita unsegmented and embryonated eggs and on second-stage juveniles, both free and included in the egg masses. The experiment, run twice, was carried out in small glass containers in the dark at a constant temperature of 25°C. The data from the two tests were statistically analysed. The clove oil extract stopped the embryogenesis of eggs and showed a complete nematicidal action against second-stage juveniles both free and of the egg masses. These properties make this product an interesting tool for a novel control strategy in nematode pest management
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